Refactoring to increase test coverage
Merge pull request #47 from lucaswoj/testcoverage

Refactoring to increase test coverage, added TypeValue::isSubtypeOf method
Added isCompiletimeEvaluable and isRuntimeEvaluable methods to the Value class
Spelling, comment fix
Renamed isRuntimeEvaluable to isSynthesizable, added unit tests
Merge pull request #36 from lucaswoj/value-evaluable

Add isCompiletimeEvaluable and isRuntimeEvaluable methods to the Value class